Portable and dismantleable concrete mixer

ABSTRACT

Dismantleable mixer for concrete and the like. The mixer has a drum of two nestable sections. For storage and shipment all parts other than the frame fit within the nested drums.

ted States Patent Susemihl Oct. 30, 1973 PORTABLE AND DISMANTLEABLE(IONCRETE MIXER [56] References Cited [76] Inventor: Rolf Susemihl,Altes Sonnenbad, UNITED STATES PATENTS 5154! ESEbQEQEWfiH 2,438,5553/1948 Gilson 259/177 R 22 il D 2 1971 2,453,583 11/1948 Muller 259/1761,443,735 1/1923 Edmondson 259/171 [21] Appl. No.: 204,037 2,944,7997/1960 Larson -259/177 R 3,158,361 11/1964 Brenneke.... 259/177 R F P[30] App [on nonty Dam Primary Examiner-Robert W. Jenkins Dec. 4, 1970Germany P 20 59 686.5 Atmrney BIythe D was et aL Dec. 4, 1970 Germany P20 59 698.9 Dec. 4, 1970 Germany P 20 59 699.0 Dec. 4, 1970 Germany P 2059 700.1 1 ABSTRACT 1970 Germany P 20 59 701-7 Dismantleable mixer forconcrete and the like. The mixer has a drum of two nestable sections.For storage [52] U.S. Cl 259/177 R and Shipment a" pal-ts other than theframe fit within [5 Int. Clthe nested drums [58] Field of Search259/171, 177, 175,

16 Claims, 14 Drawing Figures Patented Oct. 30, 1973 8 Sheets-Sheet u,vm

Patented Oct. 30,1973

8 Sheets-Sheet 3 Fig. 4

Fig. 5a

Patented Oct. 30, 1973 8 Sheets-Sheet 4 102 'IO9/ no Fig. 6

Patented Oct. 30, 1973 8 Sheets-Sheet 5 Patented Oct. 30, 1973 3,768,785

8 Sheets-Sheet a a o Patented Oct. 30, 1973 3,768,785

8 Sheets-Sheet PORTABLE AND DISMANTLEABLE CONCRETE MIXER BACKGROUND OFTHE INVENTION 1. Field of the Invention This invention relates to mixersfor concrete and the like and more particularly to a mixer which isdesigned for facile dismantling and storage in a dismantled conditionwhen not in use.

2. Prior Art Portable mixers, as such, are known. The known designs,however, are relatively expensive and complex. They are especially tooexpensive and complex for purchase by do-it-yourself type customers andassembly by such customers. Further, the components of known mixers donot fold, readily dismantle, or otherwise collapse in a manner whicheffectively minimizes the space required for storage and shipment.Accordingly, they are unduly expensive and wasteful insofar as costs ofshipment and storage space required are concerned.

SUMMARY OF THE INVENTION While portable mixers have the drawbackssummarized above and others, they nonetheless are gaining in popularityand importance as an ever increasing number of home owners constructtheir own homes and improvements to them. Accordingly, the possibilityof constructing a small, inexpensive, dismantleable mixer which can bestored and shipped in a small packageis most interesting. This isespecially so since compactness provides for low shipping costs andmakes the construction especially attractive for export business sincelow transportation costs allow the possibility of successful competitionabroad.

The present invention provides a simple, inexpensive and yet reliablemixer which is readily assembled and disassembled. The mixer, whendisassembled, packs neatly and compactly in a small carton or the likesuch as a corrugated paper board carton of rectangular configuration.The mixer can easily be assembled, even by novices, according to simpleschematic directions without impairing complete operation for a varietyof purposes and without sacrificing robustness.

The mixer of this invention has the following features, all of whichcontribute to the described advantages of it:

a. The mixer has a mixing drum composed of two parts which can be boxedone within the other.

b. A toothed crown is stamped into the rim of one drum part for drivingthe drum when assembled.

c. A motor is provided which has a protective housing. The motor housingis also composed of two parts which can be boxed one within the other.

d. The mixer frame is readily dismantled and is composed of thefollowing parts:

i. A central section the shape of a square U. The central section hasupstanding arms which are somewhat longer than the height of the largerpart of the drum. Thecentral section also has a base of a width which issomewhat greater than the largest diameter of the drum.

ii. A triangular leg and axle section is provided. This section can befastened, detachably, to one lower corner of the central section. Oneleg of the triangular section is an axle on which two wheels can berotatably mounted.

iii. A rod-like leg is provided. This leg is removably connectable tothe other lower corner of the central section.

e. Flexible, removable thin mixing blades are provided. The blades havea break crosswise centrally thereof so when under load from theagitating pressure of mixing a quantity of mortar 'or concrete, theyassume a curvature which provides an enhanced agitation action.

f. The drum parts are designed so that the smaller can be nested withinthe larger and placed within a carton. When positioned in the carton,the drum parts are sized and positioned such that the'motor and othercomponents other than the frame can be disposed within the drum parts.

g. The frame parts can be placed beside the drum parts and boxedtogether within a carrying case.

h. The drum and motor housing parts as well as the agitation blades areall stamped or drawn from thin sheet metal. The frame parts are formedfrom commercially available tubular stock or channels. The centralsection of the frame, for example, is formed from channels of U-shapedcross section. Thus, the entire assembly is fabricated from inexpensive,readily availableand light weight materials but the finished product isone which is strong and robust. i. In the preferred configuration thedrum and motor housing parts are tapered at an angle of about 8 so thatthey each are nestable in like parts for convenience in manufacture andin the mated parts for convenience in shipment and storage.

3'. The mixing blades are detachably fastened to the two mixer drumsections. Removable fasteners are used so that the mixing blades assistin rigidifying the drum. Each blade is, in turn, reinforced by the drumitself when in use, but readily removable for storage and shipment.Because the mixer drum reinforces the agitator in use, sheet metal maybe used but the mixer blades are nonetheless of more than adequatestrength for the forces encountered during mixing.

k. The mixer blades or agitators are apertured. The apertures are sizedand contoured such that the metal pieces removed to form the aperturesform other parts of the mixer as will be described in greater detailpresently.

1. The provision of a novel shaft and bearing assembly for supportingthe mixing drum. A pair of dish-shaped members are provided. Thesedishshaped members are formed of sheet metal by stamping or drawing andeach includes a bearing supporting recess. Shaft bearings are disposedin these recesses and the mixer support shaft is journaled in thebearings. Snap rings are provided to maintain the bearings in spacedrelationship and within the supporting dishes. The dishes are securedtogether at perimetral flanges, when flanges in turn are removablyfastened to the base of the mixer by removable fasteners. Thus, theremovable and inexpensive bearing and shaft assembly is provided thatboth exhibits good strength properties and shields the bearings fromcontamination by dirt or other foreign matter.

m. A simple, highly reliable and dependable drive is provided. Asindicated in b), above, a toothed crown is provided. To accomplish this,one of the mixer drum parts is equipped with a notched perimetralflange. The flange forms an annular rack for receiving the teethof adrive pinion. The flange, when stamped to form the rack, is formed insuch away that the teeth of a drive pinion will not be abraded or cut bymetal defining the rack openings. A plastic pinion is then used to goodadvantage. to provide quietness of operating characteristics. v Onemanner in which the possibility of abrasion and cutting of the pinionteeth is obviated is by providing upturned rack portions on the side ofeach pinion-tooth-receiving aperture that is engaged by a pinion toothwhich extend further than the upturned portions on the opposite side ofeach such aperture. Thus, the-metal deformed outwardly to form eachaperture is in two portions on either side of the aperture. The toothengaging one of the portions is larger than the opposite portion so asto obviate any possibility of the top of the tooth engaging portionabrading a tooth.

. Preferably, this rack is formed on the flange on a lower one of thetwo drum parts. The upper drum part has an annular perimetral flangewhich overlies the rack and shields it from material which may bedropped when the mixer is loaded or unloaded and thus keeps the pinionand the" rack clean.

. Annular pads or gaskets are secured to the upper drum flange. Thesegaskets provide fluid-tight drum walls when the drum sections are fixedtogether.

. As has been indicated, the motor housing is comprised of two flangeddrawings or stampings which nest together for storage. When the flangesare connected together, a very rigid motor housing is provided althoughmade of sheet steel. Alternately, especially where a gasoline engine maybe used, the two parts may be hinged together to permit access forservice. Slots are formed in the walls of the housing for receivingmotor mounting bolts so'that the motor may be adjusted for example totension a drive V belt, while the housing is maintained in assembled andclosed condition.

. A novel bearing construction which is simple and readily dismantleablebut adequately and properly supports the mixer support yoke is providedas are facilely removable wheels which further contributes to a readilydismantleable construction.

The cooperation of all of these features makes it possible to pack themixer in an ideally small package. The size of the package is determinedprimarily only by the dimensions of the larger part of the drum which ispreferably the lower drum part. Except for the frame parts, all of themixer components are placed within the nested drum parts for packagingand shipment or storage. The frame parts are made so that they packneatly and compactly around the drum parts to provide a very simple andcompact overall construction.

Other objects and a fuller understanding of the invention may be had byreferring to the following description and claims taken in conjunctionwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of theassembled mixer;

FIG. 2 is a side elevational view, with parts broken away and removed,of the assembled mixer;

FIG. 3-is an enlarged fragmentary view, partly in section, of the drumsupport and shaft and bearing assemy;

FIGS. 4, 5 and 5a are enlarged fragmentary sectional views of the rackand pinion arrangement used to rotate the mixing drum;

FIG. 6 is an enlarged sectional view of the motor housing as seen fromthe plane indicated by the line 6-6 of FIG. 2;

FIG. 7 is an enlarged side elevational view, with parts broken away andremoved, of an alternate form of motor housing;

FIGS. 8 and 8a are enlarged views of the agitator;

FIG. 9; is a perspective view of a partially packed case, with aportion, of the case broken away and removed for clarity ofillustration;

FIG. 10 is a perspective view of the packed case, with a portion of thecase broken away and removed for clarity of illustration; and,

FIG. 11 is an enlarged elevational view of the mixer yoke supportassembly.

FIG. 11a is an enlarged sectional view taken along the lines A-B of FIG.11.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings and toFIGS. 1 and 2 in particular, the portable, dismantleable mixer is showngenerally at 10. The mixer has a sectionalized frame shown generally at11. The frame 11 supports a generally U-shaped mixer yoke 12. The mixer10 has a mixing drum supported by the yoke 12 and composed of upper andlower drum sections l3, 14. The upper section 13 has a load anddischarge opening 15 through which material passes to and from a mixingchamber within the drum. The drum is journaled on a shaft 16 forrotation about an axis-which, in the orientation shown in the drawings,is vertical. I

A motor 17 is provided. The motor is housed within a motor housingcomposed of sections 18, 19. The housing is mounted on the frame 11 byconnection of the section 18 to it. The motor drives the mixing drum ina manner which will be described in greater detail.

The frame 11 has a central section composed of a horizontally extendingbase 20 and a pair of upwardly extending, vertically disposed arms 21,22. The base and arms 20-22 are formed of channel members. Theconnections of the upstanding arms to the central section base arereinforced by fillets 23. A handle 24 is connected to the arm 21 tofacilitate movement of the mixer.

The frame 11 includes a single front leg 25 which is connected to thecentral section by removable fasteners such as screws 26. The frame alsoincludes a removable triangular section 27. The triangular section isfastened to the central section by removable fasteners such as screws28.

The lower leg of the triangular section 27 includes an axle 29. A pairof wheels 30 are removably attached to the axle 29 by' snap clips 31,one of which is visible in FIG. 2.

Referring now to FIG. 11, the construction of the yoke 12 is shown indetail. The yoke 12 includes a central shaft support sleeve 33. Theshaft 16 is mounted in the sleeve 33. A pair of identical arms 34, 35 ofchannels having U-shaped cross section extend diametrically oppositefrom and are connected to the shaft sleeve 33 as by welding. The armscurve upwardly, when in the orientation of FIGS. 1 and 2, such that thesleeve 33 and the connected arms 34, 35 together form the generallyU-ahaped yoke.

A pair of shaft and journaling sleeves 36, 37 are provided. The shaftand journaling sleeves have extensions 38, 39, respectively, which arefixed to the yoke arms 34, 35, respectively. The shaft and journalingsleeves 36, 37 are journaled in collars 40, 41, respectively. Thecollars 40, 41 have depending extensions 42, 43 which are removablyconnected to the central frame section arms 21, 22 respectively. Thisremovable connection is by removable fasteners such as screws 44.

A handle shaft 45 is provided. The handle shaft projects through shaftand journaling sleeve 36. A handle collar 46 is in telescopicrelationship with the shaft and journaling sleeve and the handle shaft45. A stop 47 engages the shaft so that, the sleeve 36 and the collar 46are fixed together in non-rotatable relationship. A handle connectingand tilt control element 48 is pivotally connected by a pivot pin 49 tothe handle collar 46. A handle 50 is secured to the tilt control element48.

A tilt control plate 52 is provided, FIG. 2. The tilt control plate 52is secured to the collar 40 to maintain it in a fixed position. The tiltcontrol plate 52 has perimetral notches 53 which are selectivelyengageable at least one at a time, by at least a notch projection 54 ontilt control element 48. Thus, the handle may be rotatedcounterclockwise as viewed in FIG. 2 about the axis of the pivot 49until the tilt plate is disengaged. The handle is then rotated about theaxis of the journaling sleeves 36, 37 to adjust the mixing drum axis toa desired angular relationship with respect to the vertical. The handleis then rotated clockwise about the pivot 49 to bring the at least onenotched projection 54 into appropriate and selected one or ones of thenotches 53 and lock the mixing drum in its adjusted position.

It will be appreciated that, in connection with the packaging of theentire mixer when dismantled as described presently, the handle may bepivoted until it is parallel to and juxtaposed near the central sectionleg 21. Alternatively, the handle may, if desired, be removed forstorage by removal of the pivot pin 49.

A drive shaft 55 is provided. The drive shaft 55 is journaled in theshaft and journaling sleeve 37. The drive shaft 55 carries a pinion 57at its inner end. As will be explained in greater detail presently, thepinion 57 rotatively drives the mixing drum.

The journaling support for the mixing drum is best shown in FIG. 3.Upper and lower dish-shaped drum support members 59, 60 are provided.The drum support members 59, 60 have bearing support recesses 61, 62.The recesses receive shaft bearings 63. The drum shaft 16 projectsthrough an aperture 65 in the lower member 60 and into the shaftbearings 63. The shaft bearings 63 are maintained in spaced relationshipby a pair of snap rings 64 that are mounted in grooves on the drumshaft.

The drum support members have perimetral flange portions 67, 68 whichnest together. The flange portions are removably fixed together and tobottom 70 of the lower drum section 14 by fasteners identifiedschematically at 71. The bearing support members 59, 60 are formed suchthat a slight axial loading is applied to the bearing 63 when the entireassembly is connected together and secured to the lower drum section I4.

As an examination of FIG. 3 will further show, the bottom of the lowerdrum section 14 has a central portion 72 which is convex as viewed fromthe interior of the drum. This convex portion '72 provides clearance forthe shaft and bearing assembly and in addition tends to rigidify thebottom 70 of the drum section 14.

Referring now to FIGS. ll-5a, the upper and lower drum sections 13, 14have mating perimetral flanges 74, 75. Annular seals or gaskets 76, 77are carried by the upper flange 74 and interposed between the flanges74, 75 to provide a perimetral seal when the drum sections are fixedtogether. The drum sections are removably fixed together by nuts andbolts 78.

The lower drum section flange 75 has a plurality of rack teeth formed init. These rack teeth are formed by deforming the flange 75 to definepinion-toothreceiving apertures 81 and tooth surfaces surrounding theapertures. Preferably, the deformed metal defining end walls of eachtooth aperture provides rounded headings or tooth sides 82. Thepreferred construction of the end walls is shown in FIG. 5a. There tooth80' has a tooth-engaging portion 84 which is of greater verticaldimension, as viewed in FIG. 5a, than the opposite portion 85 and thanthe engaged tooth of the pinion. This assures the avoidance of the edgesof the toothengaging portion 84 being kept out of contact with teeth ofthe pinion 47. Further, the tooth-engaging portions 84 are curved tominimize pinion tooth slip. Accordingly, pinion tooth abrasion andcutting are minimized and avoided and outstanding and quiet performancecan be achieved with a pinion formed of nylon or other suitable plasticmaterial.

The upper flange 74 is contoured to provide a covering portion 86 toprotect the rack and pinion from the egress of dirt. In addition,perimetral portions of the flanges 74, 75 are oppositely bent to providenesting perimetral reinforcement portions 87.

Referring now to FIGS. 2, 8 and 80, at least one and preferably aplurality of mixing agitators 89 are provided. As is best seen byreference to FIGS. 8 and 80, an agitator or mixing blade 89 is formed ofsheet metal with a break at 90 centrally located longitudinallyspeaking. The blade 89 also has breaks at 91, 92 to provide end mountingflanges 93, 94.

The mounting flange 93 is secured to the lower drum section by thefasteners 71 which mount the bearing and shaft assembly. The mountingflange 94 is an upper mounting flange fixed to the upper drum section byremovable fasteners at a location indicated schematically at 95. When inplace, the agitators serve to reinforce the drum sections and maintainthem in position and vice versa.

The agitators have agitation apertures 96, 97, 98 through which theconcrete or other material being mixed can pass during the agitation.Thus, the agitator 89 when apertured has elongated strips 99 andtransverse strips 100 which serve to stir the material being mixed.

Under the load of mixing, the agitators tend to assume a generallycurved configuration thoroughly mixing the material and causing thematerial to work upwardly providing a thorough agitation. While theagitators in the drum sections are formed of sheet metal, the uniqueconstruction which has been described provides a great rigidity which ismore than ample for the forces imposed during the mixing.

As a further example of the efficiency and novelty of the design of thismixer, the metal portions removed from the mixer 89 to provide theagitation apertures are used for other purposes in the mixer. Thus, thepiece removed to form the aperture 96 is used to form one of the centralsection fillets 23. Similarly, the pieces removed to form apertures 97,98 are used in connection with the motor mounting bracket which will bedescribed presently.

Referring now to FIGS. 2 and 6, the motor is supported on a motorbracket 102. The motor bracket 192 has upstanding mounting flanges 103which are slotted at 105 to receive motor bracket mounting bolts 104,FIG. 2. The motor bracket mounting bolts are accessible from the outsideof the motor housing so that tension on a V-belt 106 can readily beadjusted. The V- belt 106 is reeved around a motor pulley 107 mounted onthe shaft of the motor and a drive pulley 108 mounted on the drive shaft55. The pulleys and belt are disposed within the motor housing.

Motor mounting bracket 102 has edge flanges 108 and a central rib 109for providing bracket stiffness and reinforcement. As is best seen inFIG. 6, the bracket is curved so that a segment of it is of the contourof the motor 17 and the motor is bolted to the bracket as by bolt 110.An aperture 111a is provided in the motor housing section 19 so thatelectrical leads are readily connected to the motor.

The motor housing, like the mixer section, is made of two sheet metalformed elements 18, 19. The housing, like the mixer drum, has perimetralwalls which taper at about 8 or more so that, when dismantled, the motorhousing and the drum have sections which nest one within the other. Inaddition, like sections can, for inventory control and production, bestored in a nested arrangement.

The motor housing stiffening is provided by perimetral flanges 111, 112and by depressions 113 formed in the walls thereof. The flanges 111, 112are removably secured together by removable fasteners indicatedschematically at 115.

Referring now to FIG. 7, an alternate form of housing construction isshown. Here, the housing sections 13, 19 are hingedly connected togethernear their base by a hinge 117. A catch is indicated schematically at118 which serves to fix the flanges 111, 112 of the housing sectionstogether. This construction is used advantageously when, for example, agasoline motor is used to power the mixer. Then, of course, ready accessto the engine for service is desirable.

Where the housing of FIG. 7 is employed, it is desirable to mount themotor directly on the frame arm 22. Accordingly, a motor bracket 120 isprovided which is removably secured to the frame arm 22 by bolts 121. Aswill be recognized by an examination of the drawing, portions of themotor bracket 120 are formed from the metal removed to form theapertures 97, 98 in the agitator 89.

near the center of the packing case as shown in FIG. 9. Variouscomponents of the mixer are then positioned in the motor housing. Thus,in FIG. 9, the tilt plate 52, the motor bracket 102, the motor 17, andits pulley 107, and the handle 50 are all shown in the nested motorhousing sections. The wheels 30 are also shown in the case and these mayalso be positioned in the motor housing if desired. After these elementshave been positioned in the case, the upper drum section is placed overthem. The lower drum section, with mixer yoke 12 still attached ifdesired, is then inverted and nested over the upper drum section. Theframe sections, after the frame has been dismantled, are then positionedin the case and the entire mixer has been dismantled and convenientlypackaged within the case 125 as shown in FIG. 10.

Although the invention has been described in its preferred form with acertain degree of particularity, it is understood that the presentdisclosure of the preferred form has been made only by way of exampleand that numerous changes in the details of construction and thecombination and arrangement of parts may be resorted to withoutdeparting from the spirit and the scope of the invention as hereinafterclaimed.

What is claimed is:

l. A dismantleable mixer for conrete or the like which can be packed ina shipping container when dismantled comprising:

a. a frame;

b. said mixer frame being comprised of dismantleable sections;

c. a drum yoke supported on the frame;

d. a sectioned drum journaled on the yoke for rotation about itslongitudinal axis by two bearings disposed within a pair of bearingsupports one of which lies in a recess provided for it in the drum, saiddrum including a rack for receiving driving forces to rotate the drum;

c. said drum sections having flange means joined detachably to form saiddrum such that the drum defines a mixing chamber; and,

f. drive means drivingly connected to the rack for rotating the drum.

2. The mixer according to claim 1 wherein both bearing supports aresubstantially alike and are made of thin sheet metal.

3. A dismantleable mixer for concrete or the like which can be packed ina shipping container when dismantled comprising:

a. a frame;

b. said mixer frame being comprised of dismantleable sections;

c. a drum yoke supported on the frame;

(1. a sectioned drum journaled on the yoke for rotation about itslongitudinal axis, said drum including a rack for receiving drivingforces to rotate the drum;

e. said drum sections having flange means joined detachably to form saiddrum such that the drum defines a mixing chamber;

f. drive means drivingly connected to the rack for rotating the drum,said drive means including a motor; and,

g. a protective housing for the motor, said housing comprising a housingsection mounted on the mixer frame and another housing section similarin form butdiffering in size by about the thickness of the sheet metalused, said housing sections having flange means joined detachablytogether.

4. The mixer according to claim 3 wherein stiffening profiles areprovided in the motor protection housing sections.

5. The mixer according to claim 3 wherein the motor is mounted on amotor bracket height-adjustably fastened to the motor housing.

6. The mixer according to claim 3 wherein the motor is on a bracketfastened detachably to only one housing part and to the mixer frame.

7. A dismantleable mixer for concrete or the like which can be packed ina shipping container when dismantled comprising:

a. a frame;

b. said mixer frame being comprised of dismantleable sections;

0. a drum yoke supported on the frame;

d. a drum comprised of two sections detachably connected together withremovable fasteners, one of said sections being nestable within theother when detached,

e. a rack on said drum for receiving driving forces to rotate the drum;

f. said drum sections having flange means joined detachably to form saiddrum such that the drum defines a mixing chamber; and,

g. drive means drivingly connected to the rack for rotating the drum.

8. The mixer of claim 7 wherein both of the sections taper from acomparable large diameter at a juncture between the sections and eachsection is of generally comparable size to the other.

9. The mixer of claim 8 including journal means establishing an axistransverse to said longitudinal axis about which the drum can be tiltedand wherein the juncture from which both sections taper essentiallyintersects the tilting axis of the drum.

10. The mixer of claim 8 wherein both sections taper at an angle of atleast 8.

11. The mixer according to claim 7 wherein a mixing blade is in saidchamber and secured to the drum.

12. The mixer of claim 11 wherein the mixer blade is one piece andstamped from thin sheet metal and is fastened between drum sections bymeans of end flanges.

13. A dismantleable mixer for concrete or the like which can be packedin a shipping container when dismantled comprising:

a. a frame;

b. said mixer frame being comprised of dismantleable sections;

c. a drum yoke supported on the frame;

d. a sectioned drum journaled on the yoke for rotation about itslongitudinal axis, said drum including a rack for receiving drivingforces to rotate the drum;

e. said drum sections having flange means joined detachably to form saiddrum such that the drum defines a mixing chamber; and,

f. pinion drive means drivingly connected to the rack for rotating thedrum;

. said rack being formed in the flange means of one of said drumsections by oblong holes with side surfaces formed from bent flangematerial, one side surface extending from the said flange means agreater distance than the other and beyond teeth of the engaging piniondrive means.

14. The mixer of claim 13 wherein there are upper and lower drumsections and said one drum section is the lower and wherein the upperdrum section flange means is a perimetral flange overlying the rack toshield it.

15. The mixer according to claim 14 wherein perimetral portions of theflange means are bent in a stiffening manner.

16. In combination:

a. a packing case having a base; and,

b. an assembleable cement mixer within the packing case comprising:

i. two mixing drum sections of substantially similar size one nestedwithin the other in an opposite orientation from that in which it isassembled to form the drum, said sections supported on the base of thecase,

ii. a plurality of cement mixer parts, including a motor and driveassembly, a housing and support means for the motor and drive assembly,and a mixer drum journaling assembly, all within one of the nestedsections, and

iii. a dismantled frame within said packing case, the

components of said disassembled frame being external of the mixing drumsections.

1. A dismantleable mixer for conrete or the like which can be packed ina shipping container when dismantled comprising: a. a frame; b. saidmixer frame being comprised of dismantleable sections; c. a drum yokesupported on the frame; d. a sectioned drum journaled on the yoke forrotation about its longitudinal axis by two bearings disposed within apair of bearing supports one of which lies in a recess provided for itin the drum, said drum including a rack for receiving driving forces torotate the drum; e. said drum sections having flange means joineddetachably to form said drum such that the drum defines a mixingchamber; and, f. drive means drivingly connected to the rack forrotating the drum.
 2. The mixer according to claim 1 wherein bothbearing supports are substantially alike and are made of thin sheetmetal.
 3. A dismantleable mixer for concrete or the like which can bepacked in a shipping container when dismantled comprising: a. a frame;b. said mixer frame being comprised of dismantleable sections; c. a drumyoke supported on the frame; d. a sectioned drum journaled on the yokefor rotation about its longitudinal axis, said drum including a rack forreceiving driving forces to rotate the drum; e. said drum sectionshaving flange means joined detachably to form said drum such that thedrum defines a mixing chamber; f. drive means drivingly connected to therack for rotating the drum, said drive means including a motor; and, g.a protective housing for the motor, said housing comprising a housingsection mounted on the mixer frame and another housing section similarin form but differing in size by about the thickness of the sheet metalused, said housing sections having flange means joined detachablytogether.
 4. The mixer according to claim 3 wherein stiffening profilesare provided in the motor protection housing sections.
 5. The mixeraccording to claim 3 wherein the motor is mounted on a motor bracketheight-adjustably fastened to the motor housing.
 6. The mixer accordingto claim 3 wherein the motor is on a bracket fastened detachably to onlyone housing part and to the mixer frame.
 7. A dismantleable mixer forconcrete or the like which can be packed in a shipping container whendismantled comprising: a. a frame; b. said mixer frame being comprisedof dismantleable sections; c. a drum yoke supported on the frame; d. adrum comprised of two sections detachably connected together withremovable fasteners, one of said sections being nestable within theother when detached, e. a rack on said drum for receiving driving forcesto rotate the drum; f. said drum sections having flange means joineddetachably to form said drum such that the drum defines a mixingchamber; and, g. drive means drivingly connected to the rack forrotating the drum.
 8. The mixer of claim 7 wherein both of the sectionstaper from a comparable large diameter at a juncture between thesections and each section is of generally comparable size to the other.9. The mixer of claim 8 including journal means establishing an axistransverse to said longitudinal axis about which the drum can be tiltedand wherein the juncture from which both sections taper essentiallyintersects the tilting axis of the drum.
 10. The mixer of claim 8wherein both sections taper at an angle of at least 8*.
 11. The mixeraccording to claim 7 wherein a mixing blade is in said chamber andsecured to the drum.
 12. The mixer of claim 11 wherein the mixer bladeis one piece and stamped from thin sheet metal and is fastened betweendrum sections by means of end flanges.
 13. A dismantleable mixer forconcrete or the like which can be packed in a shipping container whendismantled comprising: a. a frame; b. said mixer frame being comprisedof dismantleable sections; c. a drum yoke supported on the frame; d. asectioned drum journaled on the yoke for rotation about its longitudinalaxis, said drum including a rack for receiving driving forces to rotatethe drum; e. said drum sections having flange means joined detachably toform said drum such that the drum defines a mixing chamber; and, f.pinion drive means drivingly connected to the rack for rotating thedrum; g. said rack being formed in the flange means of one of said drumsections by oblong holes with side surfaces formed from bent flangematerial, one side surface extending from the said flange means agreater distance than the other and beyond teeth of the engaging piniondrive means.
 14. The mixer of claim 13 wherein there are upper and lowerdrum sections and said one drum section is the lower and wherein theupper drum section flange means is a perimetral flange overlying therack to shield it.
 15. The mixer according to claim 14 whereinperimetral portions of the flange means are bent in a stiffening manner.16. In combination: a. a packing case having a base; and, b. anassembleable cement mixer within the packing case comprising: i. twomixing drum sections of substantially similar size one nested within theother in an opposite orientation from that in which it is assembled toform the drum, said sections supported on the base of the case, ii. aplurality of cement mixer parts, including a motor and drive assembly, ahousing and support means for the motor and drive assembly, and a mixerdrum journaling assembly, all within one of the nested sections, andiii. a dismantled frame within said packing case, the components of saiddisassembled frame being external of the mixing drum sections.